An investigation report said the child was sitting in a car seat placed in front of a GMC Yukon and the vehicle rolled forward, running over the child with the front tire.

The report said several people rushed to pick up the SUV, and someone was able to pull the child from under it.

The 4-month-old was transported to Blank Children’s hospital, where he was pronounced dead.

Officers noticed beer cans and liquor bottles scattered along the fence on the property. The car seat the child was in was also on the property, and police reported blood at the top of the car seat where the child’s head would have been, the report said.

Officials said 33-year-old Deanthony Clark was loading several children in the SUV, and he was behind the wheel when he put the vehicle in gear and ran over the child.

Police said they do not believe Clark ran over the child intentionally and that he likely didn’t even know the child was there.

“This is horrendous. I mean there's really, as bad as your mind can get, there's really very few things you can probably think of that would be worse than this -- especially having to watch it happen,” said Sgt. Jason Halifax of the Des Moines Police Department.

Police reported that Clark had bloodshot, watery eyes and slurred speech. They also could smell alcohol on the man.

Police said if Clark’s blood alcohol tests show he was legally intoxicated, he could face vehicular homicide charges. There could potentially be no charges filed if tests show he was not intoxicated.